This is Perrott’s Folly in Edgbaston, Birmingham. It is said to be the inspiration for one of the two towers in J.R.R Tolkiens The Lord Of the Rings the other tower being Edgbaston Resvervoir pumping station tower. This folly was near were tolkien lived as a child.
Built in 1758 by John Perrott, It’s not known why it was built. It’s a grade 2 listed building and has been restored.